The following objective tree was determined for the project. There are three main marketing requirement followed by their sub-requirements. Each requirement contains a relative weight out of 1.
Objective Tree
The three marketing requirement are for the project to be intuitive, robust, and versatile. The most important marketing requirement is intuitiveness. The complexity of working in 3 dimensions makes it extremely important for users to be able to work in a way that feels natural. Components can be damaged if the robot is not operated in an expected manner. It is also important for the robot to be robust. This will help extend to robots work life and make failure less likely. Finally, the robot must also be versatile. While the focus of this project is PCB repair, the delta robot platform will lend itself to many applications. By creating this open source platform, others will be able to extend the usability of the delta robot.
Piecewise comparisons were used to determine the weights as shown below.
Piecewise Comparisons
1.3.2 - Microprocessor Functionality
The main microprocessor, an ARM Cortex 11 on the Raspberry Pi, will primarily be responsible for controlling the three stepper motors for the delta robot. This objective will be achieved by creating a gcode interpreter written in C. Gcode is a standard way to instruct a CNC router to move the work head throughout a 3D space, but is more complicated than accepting individual commands to move the motors. The microprocessor will be responsible for scheduling movements to make smooth transitions to the destination, as interpreted from the gcode. Instead of having physical buttons or a local user interface, the system will mainly be a network device, connected through WiFi or Ethernet. The microprocessor will obtain gcode commands through local storage or by accepting gcode files over HTTP or SSH. The gcode received over HTTP or SSH may then be optionally stored locally for faster use again in the future. Execution of gcode sequences will be started through an HTTP interface, meaning any device with a browser can interact with the system. All network interfaces will be password protected and use encryption algorithms to ensure that all commands executed are from authorized users.
A secondary microprocessor may be required to control the tools on the delta robot, including the heat of a soldering iron, the rotation of a drill bit, or the positioning of cameras based on the user's position. This secondary microprocessor will perform any required communication with the network-connected main microprocessor through a serial interface.
1.3.3 - Telecommunications Functionality
The telecommunications requirements for the project will be sending data from the Oculus Rift to a centralized computed where it will be converted to movement data for the operation of the Delta Robot. Video information must also be sent from the computer to the Oculus Rift. The movement data will be transmitted from the central computer to the Delta Robot via Ethernet. Video data from the Delta Robot will be transmitted to the computer by a video channel such a S-video. The Oculus Rift will use a USB channel to transmit data to the computer while the computer will use a DVI channel to transmit the video data to the Oculus Rift.
Telecommunication Model
1.3.4 - CEEN Appropriateness
The senior capstone design project serves as part of the ABET accreditation for the CEEN program. To meet these standards, students at the time of graduation will have:
an ability to apply knowledge of mathematics, science, and engineering. (ABET 3a)
an ability to design and conduct experiments, as well as to analyze and interpret data. (ABET 3b)
an ability to design a system, component, or process to meet desired needs within realistic constraints such as economic, environmental, social, political, ethical, health and safety, manufacturability, and sustainability. (ABET 3c)
an ability to function on multidisciplinary teams. (ABET 3d)
an ability to identify, formulate, and solve engineering problems. (ABET 3e)
an understanding of professional and ethical responsibility. (ABET 3f)
an ability to communicate effectively. (ABET 3g)
the broad education necessary to understand the impact of engineering solutions in a global, economic, environmental, and societal context. (ABET 3h)
a recognition of the need for, and an ability to engage in life-long learning. (ABET 3i)
a knowledge of contemporary issues. (ABET 3j)
an ability to use the techniques, skills, and modern engineering tools necessary for engineering practice. (ABET 3k)
In the design process of the Delta Robot, several of these requirements will be met. The design and construction will require the rigorous application of mathematics, science, and engineering for the software, hardware, mechanical, and system control. (ABET 3a). Notably, the kinematics of the robot will require intense mathematical computations to ensure accuracy. Experiments must be designed and conducted to ensure proper operation of components and the final result (ABET 3b). The end result of the project will meet the needs outlined in the Background Summary (ABET 3c). The level of success of the project will depend on how well the the team is able to cooperate and strive to achieve common goals (ABET 3d). This project will present many engineering problems that will have to be solved (ABET 3e). Not only must the group work towards common goals, but they must also communicate effectively (ABET 3g). Similarly to ABET 3a, the entire project will involve the use of engineering skills that have been learned in previous coursework (ABET 3k).
The senior capstone project also serves as a culmination of the CEEN curriculum. Concepts and skills learned in previous courses must be applied in the design, construction, and documentation of the project. Courses that will be built upon in the design of the Delta Robot are:
Microprocessor Applications
Electrical & Electronic Circuits
Communication Systems
Signals & Linear Systems
Digital Design & Interface
Microprocessor System Design
Embedded Microcontroller Design
Overall, the Delta Robot is a very technically challenging project that will require many of the skills that have been taught throughout the CEEN curricula. The completion of this project alone will meet at least 7 of the 11 ABET accreditation criteria.
1.3.5 - Constraints
1.3.5.1 -Identification
There will be many constraints in the design of this project. Most notably are time and money. As full-time students with part-time jobs, our time has to be split among many areas. Also, there are only 7-8 months to finish the project. Therefore, time must be carefully scheduled as a group for work on the project. Much of the time spent working will have to be on an individual basis. The scope of the project must be carefully decided so as to not accrue an impossible time requirement. This project if being funded entirely by the engineering team. Again, as full-time students with part-time jobs, our funds are limited. Therefore, cost will play a large role in determining which components to buy. Solutions must be carefully thought out to avoid rework and wasting money spent.
Other constraints will be safety, manufacturability, robustness, and versatility as described in the Background Summary.
The primary resources for the project are the four engineers. The engineers will be responsible for all design and implementation. Other resources that will be used include a senior thesis office that will be the primary work space, and a CNC PCB mill that will be used for prototyping.
1.3.5.2 - IEEE Standards
The following IEEE standards will be adhered to when appropriate.
IEEE Std 830-1998/IEEE Recommended Practice for Software Requirements Speciļ¬cations
IEEE Std 1220-2005/Standard for Application and Management of the Systems Engineering Process
A preliminary budget of $2000 has been appropriated, but is subject to change. The breakdown is as follows.
Mechanical
$1000
Other Parts and Software
$500
Other
$500
The bulk of the cost of the project will be mechanical parts such as belts, rods, fasteners, etc. The next greatest expense is expected to be electronic components. Most software that is used is expected to be already available or free to use, but some software may need to be purchased.
1.3.5.4 - Engineering Hours
Comparing the scope and time required of previous capstone design projects, an estimated 1000 work hours will be needed to complete this project. This means an average of approximately 33 hours per week will be required.
1.3.1 - Objective Tree
The following objective tree was determined for the project. There are three main marketing requirement followed by their sub-requirements. Each requirement contains a relative weight out of 1.
The three marketing requirement are for the project to be intuitive, robust, and versatile. The most important marketing requirement is intuitiveness. The complexity of working in 3 dimensions makes it extremely important for users to be able to work in a way that feels natural. Components can be damaged if the robot is not operated in an expected manner. It is also important for the robot to be robust. This will help extend to robots work life and make failure less likely. Finally, the robot must also be versatile. While the focus of this project is PCB repair, the delta robot platform will lend itself to many applications. By creating this open source platform, others will be able to extend the usability of the delta robot.
Piecewise comparisons were used to determine the weights as shown below.
1.3.2 - Microprocessor Functionality
The main microprocessor, an ARM Cortex 11 on the Raspberry Pi, will primarily be responsible for controlling the three stepper motors for the delta robot. This objective will be achieved by creating a gcode interpreter written in C. Gcode is a standard way to instruct a CNC router to move the work head throughout a 3D space, but is more complicated than accepting individual commands to move the motors. The microprocessor will be responsible for scheduling movements to make smooth transitions to the destination, as interpreted from the gcode. Instead of having physical buttons or a local user interface, the system will mainly be a network device, connected through WiFi or Ethernet. The microprocessor will obtain gcode commands through local storage or by accepting gcode files over HTTP or SSH. The gcode received over HTTP or SSH may then be optionally stored locally for faster use again in the future. Execution of gcode sequences will be started through an HTTP interface, meaning any device with a browser can interact with the system. All network interfaces will be password protected and use encryption algorithms to ensure that all commands executed are from authorized users.
A secondary microprocessor may be required to control the tools on the delta robot, including the heat of a soldering iron, the rotation of a drill bit, or the positioning of cameras based on the user's position. This secondary microprocessor will perform any required communication with the network-connected main microprocessor through a serial interface.
1.3.3 - Telecommunications Functionality
The telecommunications requirements for the project will be sending data from the Oculus Rift to a centralized computed where it will be converted to movement data for the operation of the Delta Robot. Video information must also be sent from the computer to the Oculus Rift. The movement data will be transmitted from the central computer to the Delta Robot via Ethernet. Video data from the Delta Robot will be transmitted to the computer by a video channel such a S-video. The Oculus Rift will use a USB channel to transmit data to the computer while the computer will use a DVI channel to transmit the video data to the Oculus Rift.
1.3.4 - CEEN Appropriateness
The senior capstone design project serves as part of the ABET accreditation for the CEEN program. To meet these standards, students at the time of graduation will have:
In the design process of the Delta Robot, several of these requirements will be met. The design and construction will require the rigorous application of mathematics, science, and engineering for the software, hardware, mechanical, and system control. (ABET 3a). Notably, the kinematics of the robot will require intense mathematical computations to ensure accuracy. Experiments must be designed and conducted to ensure proper operation of components and the final result (ABET 3b). The end result of the project will meet the needs outlined in the Background Summary (ABET 3c). The level of success of the project will depend on how well the the team is able to cooperate and strive to achieve common goals (ABET 3d). This project will present many engineering problems that will have to be solved (ABET 3e). Not only must the group work towards common goals, but they must also communicate effectively (ABET 3g). Similarly to ABET 3a, the entire project will involve the use of engineering skills that have been learned in previous coursework (ABET 3k).
The senior capstone project also serves as a culmination of the CEEN curriculum. Concepts and skills learned in previous courses must be applied in the design, construction, and documentation of the project. Courses that will be built upon in the design of the Delta Robot are:
Overall, the Delta Robot is a very technically challenging project that will require many of the skills that have been taught throughout the CEEN curricula. The completion of this project alone will meet at least 7 of the 11 ABET accreditation criteria.
1.3.5 - Constraints
1.3.5.1 - Identification
There will be many constraints in the design of this project. Most notably are time and money. As full-time students with part-time jobs, our time has to be split among many areas. Also, there are only 7-8 months to finish the project. Therefore, time must be carefully scheduled as a group for work on the project. Much of the time spent working will have to be on an individual basis. The scope of the project must be carefully decided so as to not accrue an impossible time requirement. This project if being funded entirely by the engineering team. Again, as full-time students with part-time jobs, our funds are limited. Therefore, cost will play a large role in determining which components to buy. Solutions must be carefully thought out to avoid rework and wasting money spent.Other constraints will be safety, manufacturability, robustness, and versatility as described in the Background Summary.
The primary resources for the project are the four engineers. The engineers will be responsible for all design and implementation. Other resources that will be used include a senior thesis office that will be the primary work space, and a CNC PCB mill that will be used for prototyping.
1.3.5.2 - IEEE Standards
The following IEEE standards will be adhered to when appropriate.1.3.5.3 - Preliminary Budget
A preliminary budget of $2000 has been appropriated, but is subject to change. The breakdown is as follows.The bulk of the cost of the project will be mechanical parts such as belts, rods, fasteners, etc. The next greatest expense is expected to be electronic components. Most software that is used is expected to be already available or free to use, but some software may need to be purchased.
1.3.5.4 - Engineering Hours
Comparing the scope and time required of previous capstone design projects, an estimated 1000 work hours will be needed to complete this project. This means an average of approximately 33 hours per week will be required.